needed to deal with disabled nodes
-Parse "fixed io descriptors". Their use in nonsense in principle
because 10-bit decoding is implied. Hope this is not real...
-Tolerate mismatches between node size and actually used space
as long as the used size is smaller than the buffer size. There
is at least one broken BIOS which reports node sizes larger than
the used one, and windows obviously doesn't complain...
BIOS and attaches devices to it.
While it is potentially able to deal with all the motherboard ISA
devices, it is only used in hairy cases for now - laptop stuff in
particular.